Slug testing methodology?

[dgeesaman]

I now have a sizeable array of slugs to test in my FX Crown. Once you get clicking ... you know how it is. My club has a 21y indoor range.

Looking for suggestions on how to practically test them considering the gun is tunable to provide a range of velocities. I can set it for high power and assume shooting them all at one high power setting will show the good from not good. Or do you find some slugs shoot very poorly at the wrong velocity and very well at the right velocity, such that I should attempt a quick tune for each one?

Also have have both an STX liner and STX Heavy liner - worth testing the STX too?

David

 

[mtnGhost]

Having a game plan with clear end goal is invaluable to me. When I buy a rifle or barrel, I'm doing so with the intention for shooting specific ammo in a given weight & velocity range.

22cal always involves the most amount of effort, but I generally won't shoot anything until I am sure that the barrel is appropriately sized for the swaged ammo that I plan use. Equally important to me is proper seating depth (throat geometry). I don't screw around with different sizes or sizing dies for this caliber, so I stick with .217 exclusively. This saves me time, money, and grief.

I start with Cerrosafe and a mic to measure & analyze a cast of the bore (chamber and muzzle / choke). I'll also push some pellets through to get a general feel for the bore prior to running my bore scope through it (using a Hawkeye ProSlim with the 0, 35, and 90 deg attachments). The 0 and 90 help me most in identifying errors / defects that I need to correct before shooting lead through it. FWIW, the ONLY two makes of finished barrels (not talking blanks) that I've never found errors with were CZs and the LW poly slow twist. All others had tool marks or other quality control issues that had to be dealt with.

Then it's a matter of whether or not the chamber throat needs to be reamed out, lapping / polishing, re-crowning. I'll then ensure that the barrel is supported in whatever rifle i'm using in such a way that harmonics are a non-issue. Next is verifying that my slug seating depth is correct and that the ammo is loading both square and concentric to the bore at the appropriate depth. Once that is done, I tune the rifle for the target velocity (that is most desirable for the ammo + barrel).